Sea surface temperature -1.8 C is a thermal balance construct needing very cold air in especially warmer seas.

Barrow Strait Nunavut Canada

    -3 C surface air in light winds gave accretion stalling leaving brand new sea ice a darker look,  in effect to stay new, vulnerable to any wind event.    Sea water temperature warmed to -1.5 C,  a jump of +0.3 C since yesterday.  Today's lesson highlights a changed thermal balance,  because air temperature has increased substantially from -12 to -3 C.  This offered sea water column to warm the underlying top water layer.  As a result freezing has stopped:

Open sea water easily doesn't freeze at -3 C surface temperatures.  Especially because it is at -1.5 C,  the vast majority of ice formed at colder normal -1.8 C.  Cooler surface temperatures will eventually cause top sea water to be at -1.8 C.  But for this to happen,  it usually requires sustained cooling at -11 C,  because the water column has been warmed all summer. Once top of water hits -1.8 C it solidifies.  Afterwards, further cooling is needed as sea ice thickens,  in order to always achieve the needed  -1.8 C, otherwise further down sea warmth increases the top water layer temp.  High Arctic warm heat source in October is usually from the sea,  therefore a tendency for sea water to maintain its column temperature needs to be vanquished by extremely cold air.

        Coincidentally, warming of the Canadian Arctic Archipelago came from the North! Today in darkness around the North Pole,  a similar play in physics occurred:

     CMC October 5 18z 2016,  surface air temperatures over the Arctic Ocean were extraordinarily +15 C or more above normal,  air temperatures so high,  even in darkness affect the thermal balance at sea level, especially bringing out the nature of the new sea ice recently formed.  Many sea surface water temperatures locations  jumped from -2 to -1 C:

CMC SST readings September 5 2016,  Arctic Ocean sea surface temperatures warmed along with air surface temperatures,  a well insulated  sea surface with thick sea ice on top would not have reacted  so readily,  but has done the same as like further South in Barrow Strait Nunavut Canada.  WD Oct 5 , 2016